Changing this to a "feature request", since it's certainly not a bug.

I can see both sides of this; on the one hand, <fdopen> isn't the most descriptive string and doesn't give you an idea where it came from; on the other hand, you lose the distinction between files opened by filename and those by file descriptor.

If the purpose is to distinguish between fdopen()'d files, what if fdopen() was changed so that the filename matched <fdopen \d+>, where \d+ is the file descriptor passed to fdopen()?